Dar is a shell command that makes backup of a directory tree and files. Its features include splitting archives over several files, DVD, CD, ZIP, or floppies, compression, full or differential backups, strong encryption, proper saving and restoration of hard links, extended attributes, file forks, Door inodes, and sparse files, remote backup using pipes and external commands (such as ssh), and rearrangement of the "slices" of an existing archive. It can run commands between slices, before and after saving some defined files or directories (for a proper database backup, for example), and quickly retrieve individual files from differential and full backups. Several external GUIs exist as alternatives to its CLI interface, like kdar, DarGUI, SaraB, etc.
rlimit is a program that lets you run processes with system resource limits set. It can be used by software developers and testers to test that software will run correctly in resource restricted environments. It is also useful for software which would otherwise consume excessive resources such as programs that used 100% CPU, set their own priority levels, or consume too much memory. This is basically a command line interface to the system functions getrlimit() and setrlimit().
John the Ripper is a fast password cracker, currently available for many flavors of Unix, Windows, DOS, BeOS, and OpenVMS. Its primary purpose is to detect weak Unix passwords. It supports several crypt(3) password hash types commonly found on Unix systems, as well as Windows LM hashes. On top of this, lots of other hashes and ciphers are added in the community-enhanced version (-jumbo), and some are added in John the Ripper Pro.
Nyagua is a little piece of software that may help you to manage your home aquarium. It can store data about measurements in aquariums and produce graphs from these. It can store data about expenses and produce a report with yearly, monthly, and daily costs. It reports the compatibility between fishes and plants in its database. It can import fishbase.org XML data, and your own pictures can be added.
SILVERCODERS DocToText is a powerful utility which can convert documents in many formats to plain text. It includes a console application and C/C++ library, which allows embedding text extraction mechanisms into other applications. It supports MS Office binary formats (MS Word (DOC), MS Excel (XLS, XLSB), MS PowerPoint (PPT), and Rich Text Format (RTF)), OpenDocument formats (text documents (ODT), spreadsheets (ODS), presentations (ODP) and graphics (ODG)), Office Open XML formats (MS Word (DOCX), MS Excel (XLSX), and MS PowerPoint (PPTX)), iWork formats (PAGES, NUMBERS, KEYNOTE), OpenDocument Flat XML formats (FODP, FODS, FODT), Portable Document Format (PDF), Email files (EML), and HyperText Markup Language (HTML). DocToText can extract text not only from the document body but also from annotations (comments) embedded in odt, doc, docx, or rtf files and read metadata like author, last modification date, or number of pages. It can be used as a fast console viewer, and is able to convert corrupted OpenDocument and Office Open XML documents. It can be used to recover text even if other recovery methods failed.
keychain helps you to manage ssh keys in a convenient and secure manner. It acts as a frontend to ssh-agent and gpg-agent, but allows you to easily have one long running ssh-agent process per system, rather than the norm of one ssh-agent per login session. This dramatically reduces the number of times you need to enter your passphrase. With keychain, you only need to enter a passphrase once every time your local machine is rebooted. keychain also makes it easy for remote cron jobs to securely "hook in" to a long running ssh-agent process, allowing your scripts to take advantage of key-based logins.
SubnetMapper is an admin's quick tool to map and keep track of managed IP networks, track free ranges that are available for assigning, and document the network setup. It has been designed to help admins manage and document small to medium networks. It prints and displays freely colorable maps of your network.
Terminal Mixer allows sharing the stdin/out/err of a process through a Unix socket, TCP, or raw ethernet (the latter only on Linux). It allows sharing a pseudo-terminal as well, for terminal-aware applications. The users can be allowed only to watch, or even to contribute. You can run your favourite 'vim' or 'bash' and access it remotely, even with multiple users using them.